Assig-noe



-W. H. JOHNSTONE.

Surgical Splint.

Patent d Feb. 15,1ss1.j

Aiiesis NJETERS, PHOTO-LITHDGRAPNER WASHINGTON, D c.

UNITED STATES PATENT FFICE.

WILLIAM H. JOHNSTONE, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO WILLIAM E. BLOODGOOD, OF PLAINFIELD, NEW JERSEY.

SURGICAL SPLINT.

SPECIFICATION forming part of Letters Patent No. 237,751, dated February 15, 1881 Application filed July 28, 1879.

To all whom it may concern:

Be it known that 1, WILLIAM HAMPDEN JOHNSTONE, of the city of Philadelphia, State of Pennsylvania, have invented certain new and useful Improvements in Felt for Surgical Splints and Analogous Purposes; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being bad to the accompanying drawings, mak- I ing part hereof.

The nature of my invention will appear from the following specification and claims.

The object of my invention is to produce a compound felt consisting of several fibrous layers or laps which is capable of being used for surgical splints and analogous purposescorsets, for instanceafelt adapted to receive a stiffening solution-say of shellacand to hold it within one of the layers away from the surface, so that the surface felt will not be hard or harsh, but soft and fibrous, while the shellac will be contained in the interior, the fabric to be so manipulated, when treated with the solution, as to evenly distribute the shellac,

prevent it from cakin g or lumping, and so as to leave the result comparatively porous and free from a surplusage of shellac, retaining a quantity only necessary to insure the requisite stiffness.

To enable others skilled in the art to make and use my invention, I will describe its con.- struction.

In the drawings, Figure l is a perspective view of a piece of my first layerthe layer 5 whichfirst comes from the carding-engine;

Fig. 2, a similar view of the first and second layers; Fig. 3, a similar View of three layers ready for felting.

A O are the two outer layers of long fibers.

B is an intermediate layer of short fibers.

There are several processes of felting fibers of material in layers so as to form a finished fabric of felt cloth, and while I do not limit myself to the precise method herein described,

5 1 will detail one of these processes, together with the other parts of my invention, so as to enable others skilled in the art to make and use the same.

It is formed in sheets in the following manner: It is well known to felt-manufacturers dense than it is upon the surfaces, as the layer that the better qualities of felted fabric are made of pure woolen fiber. By means of a carding-engine I first form a lap of long-fibered wool, usually about two yards wide and twenty yards long. This lap, as it comes from the card, is laid out flat on a long platform or apron in front of the doffer of the card. This lap is shown in the drawings at A. I then card outa thicker lap of corresponding length and width, formed, however, of shorter fibers of wool, and, if desired, inferior wool,such as shoddy, and this lap is laid flat down upon the lap already formed. This short-fibered lap is shown at B in the drawings. I then make another lap similarin every respect to the one shown at A. The lap last formed (marked 0) is laid down upon the lap B, so that the two long-fibered laps A 0 form two outer layers of fiber having between them the short-fibered lap B. The three laps thus arranged may be said to form a compound lap. This compound lap is then rolled up, soaked in heated water, and is pounded and treated in the manner usually employed in felting various layers of fiber or laps. The fibers composing the contiguous surfaces of the adjoining laps become felted together, as well as the fibers composing each lap, so that when the felting operation is completed the compound lap above described becomes a homogeneous felted fabric. As the inferior short-fibered wool of the interior lap will not felt so densely as the longer-fibered wools, the interior of the felted fabric thus formed will be more open or less B will felt less closely than layers A and 0.

My felt is not made so dense as that used in hat-bodies, but is more open, soft, and porous.

The felted fabric being thus completed, itis applied as follows: If it is desired to use a piece of my felt for a splint, corset, or thelike, it must be stiffened with some solution having that effect. I cut a piece of my compound felt to about the size required for the desired pur- 5 pose. I take the piece so cut and saturate it thoroughly in a solution, say, of shellac dissolved in alcohol. Now,as the interior of this felt is more loosely felted than the outer layers, the interior will receive and retain by absorption more of the shellac than the outer parts. I then pass the piece through two calender-rolls set to just the same distance apart as is equal to the thickness of theinterior layer of feltingthat is, of the interior lap. This rolling of the saturated fabric has the effect of equalizing the distribution of the shellac, and of compressing nearly all of it out of the exterior laps and of forein g it into the interior lap, leaving the outer layers soft and smooth. The material must then be thoroughly dried. I now take the piece of saturated felt and place it in a steam-box to be softened. The action of the hot live steam upon the shellac in the felt is much to be preferred to that resulting from plunging it into hot water. Hot water is apt to cake the shellac or run ittogether in a hard caked mass, while steam gently softens it and does not destroy the porosity of the fabric.

The felt thus softened can be molded to almost any shape and to fit any irregular form, whether used as a splint in surgery or otherwise, and after-being so molded and allowed to harden it will retain rigidly the shape so given to it. Its surface will be soft and pleasant in contact with the skin.

My felt is peculiarly adapted for use in splints when so stiffened upon account of its peculiar property or capability of receiving and retaining the hardening or stiffening substance within its interior, and so of presenting a soft fuzzy surface. The difficulty with other forms of felt when so used was that, being of uniform density-that is, as dense in the interior as at and near the surface-the shellac could scarcely penetrate to the interior, and remained, to a great extent, upon the surface. This, when dry, rendered the surface harsh and disagreeable to the patient. I use cold rolls to distribute the shellac. Ahls felt, when saturated with shellac, was hotironed, which melted the shellac to a very thin consistency and run it in irregular masses. My rolls are as long as the fabric which I pass through them is wide. My rolls so compress the soaked mass that immediately upon leaving the cold rolls the spring and life of the long outer fibered laps tend to lift them away from the comparatively inert inner lap, leaving the latter to hold the main part of the solution. My rolls also have a foot adjustment, so that, if desired, more shellac can be leftin the felt by not setting them so closely together. I make my central layer of a thickness about equal to that of the other two layers combined.

Heretofore an alkaline solvent has been used with the alcohol and shellac, and in preparing felt splints a sulphuric-acid bath has been used to give hardness to the shellac and to overcome the ill effects of using an alkaline solvent but this resulted invariably in giving so brittle a character to the shellac as to render it liable to snap or break instead of sprin gin It destroyed its elasticity and flexibility. I

therefore use the pure shellac, and employ only a solvent which will evaporate without any deleterious influences upon the shellac, using no bath subsequently but the steambath to soften.

In preparingmy solution I use a proportion of about four pounds of shellac to one gallon of alcohol. I usually cuta complete set of splints, consisting of fifty pieces, from twenty-eight square feet of felt. To every twenty-eight square feet of compound felt I absorb about one and one fifth gallon of the solution. Twenty-eight square feet of felt make one complete set of splints for an adult and one youths set, containing twenty-five pieces in each.

My felt can be made in two layers, though I prefer three, because I can thus have long good wool on both surfaces. If made in two layers, the shellac can be driven into the center by means of the rolls, as described above, and the surface formed of long wool can be used as the inside of the splint. The surface formed of short fibers will not be so smooth and soft as the other surface. I consider the three layers the better plan.

Having thus described my improvement, what I claim as new, and desire to secure by Letters Patent, is-

1. A compound felting formed of two or more layers of felted material, onelayer being formed of shorter fiber than the others, substantially as described.

2. A compound felting formed of two or. more layers of felted material, one layer being felted more loosely than the other, substantially as described.

3. A compound felting formed of three layers of felted material, the two outer layers being more closely felted than the interior layer, substantially as described.

4. The process of preparing the fabric for formation into a splint or jacket by first saturating it in a solution of shellac or similar material, drying it, and then steaming it to soften it, substantially as and for the purposes described.

5. The process of preparing a fabric for use in splints and analogous purposes by first saturating it in a solution of shellac or its equivalent, and then passing it between two rolls, to evenly distribute the shellac and to drive it into the interior of the fabric, substantially as described.

6. The process of preparing a fabric for use in splints by first saturating it in a solution of shellac or its equivalent, and then pressing it between two cold rolls, whereby the shellac is evenly distributed and is driven into the interior of the fabric, substantially as described.

7. In preparing a fabric for a use in which great stiffness is desired, the process of steeping or saturating it in a stiffening solution, substantially as above set forth, then passing it between two rolls adjusted to a distance apart equal, or about equal, to the thickness or space within which it is desired to retain the stiffening compound, whereby the surfaces of the fabric are kept comparatively free from the said solution, substantially as and for the purposes described.

8. A compound fabric for use in surgical splints or jackets and analogous purposes,

composed of two or more layers of texture saturated with a solution of shellac or its equivalent, srbstantially as described.

WILLIAM HAMPDEN JOHNSTONE. Witnesses:

GEo. R. THOMPSON, PIERRE J OHNSTONE. 

